Methods and systems for automatically renaming logical Circuit identifiers for rerouted logical circuits in a data network

ABSTRACT

A disclosed example method involves identifying a first logical circuit identifier for a first logical circuit in a first network. When a failure is detected in the first logical circuit, a second logical circuit identifier for a second logical circuit in a failover network separate from the first network is identified and the first logical circuit is renamed without manual intervention to identify the first logical circuit using the second logical circuit identifier. The second logical circuit is to reroute data from the first logical circuit.

PRIORITY APPLICATIONS

This patent is a continuation of U.S. patent application Ser. No. 10/745,047, filed Dec. 23, 2003, now U.S. Pat. No. 7,646,707, which is hereby incorporated herein by reference in its entirety.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent is related to U.S. patent application Ser. No. 10/348,077, entitled “Method and System for Obtaining Logical Performance Data for a Circuit in a Data Network,” filed on Jan. 21, 2003, and U.S. patent application Ser. No. 10/348,592, entitled “Method and System for Provisioning and Maintaining a Circuit in a Data Network,” filed on Jan. 21, 2003. This patent is also related to and filed concurrently with U.S. patent application Ser. No. 10/745,117, entitled “Method And System For Providing A Failover Circuit For Rerouting Logical Circuit Data In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/744,281, entitled “Method And System For Utilizing A Logical Failover Circuit For Rerouting Data Between Data Networks,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/745,170, entitled “Method And System For Automatically Identifying A Logical Circuit Failure In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/744,921, entitled “Method And System For Automatically Rerouting Logical Circuit Data In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/745,168, entitled “Method And System For Automatically Rerouting Logical Circuit Data In A Virtual Private Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/745,116, entitled “Method And System For Automatically Rerouting Data From An Overbalanced Logical Circuit In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/744,283, entitled “Method And System For Real Time Simultaneous Monitoring Of Logical Circuits In A Data Network,” filed on Dec. 23, 2003, U.S. patent application Ser. No. 10/744,555, entitled “Method And System For Prioritized Rerouting Of Logical Circuit Data In A Data Network,” filed on Dec. 23, 2003. All of the above-referenced applications are assigned to the same assignee as this patent and are expressly incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to the routing of data using logical circuits in a data network. More particularly, the present invention is related to automatically renaming logical circuit identifiers for rerouted logical circuits in a data network.

BACKGROUND

Data networks contain various network devices, such as switches, for sending and receiving data between two locations. For example, frame relay and Asynchronous Transfer Mode (“ATM”) networks contain interconnected network devices that allow data packets or cells to be channeled over a circuit through the network from a host device to a remote device. For a given network circuit, the data from a host device is delivered to the network through a physical circuit such as a T1 line that links to a switch of the network. The remote device that communicates with the host through the network also has a physical circuit to a switch of the network. A network circuit also includes a logical circuit which includes a variable communication path for data between the switches associated with the host and the remote device.

In large-scale networks, the host and remote end devices of a network circuit may be connected across different local access and transport areas (“LATAs”) which may in turn be connected to one or more Inter-Exchange Carriers (“IEC”) for transporting data between the LATAs. These connections are made through physical trunk circuits utilizing fixed logical connections known as Network-to-Network Interfaces (“NNIs”).

Periodically, failures may occur to the trunk circuits or the NNIs of network circuits in large-scale networks causing lost data. Currently, such network circuit failures are handled by dispatching technicians on each end of the network circuit (i.e., in each LATA) in response to a reported failure. The technicians manually access a logical element module to troubleshoot the logical circuit portion of the network circuit. The logical element module communicates with the switches in the data network and provides the technician with the status of the logical connections which make up the logical circuit. Once the technician determines the status of a logical connection at one end of a logical circuit (e.g., the host end), the technician then must access a network database to determine the location of the other end of the logical circuit so that its status may also be ascertained. If the technician determines the logical circuit is operating properly, the technician then accesses a physical element module to troubleshoot the physical circuit portion of the network circuit to determine the cause of the failure and then repair it.

Current methods of determining network circuit failures, however, suffer from several drawbacks. One drawback is that troubleshooting logical and physical circuits is time consuming and results in dropped data packets or cells until the failure is isolated and repaired. Furthermore troubleshooting the physical circuit often requires taking the network circuit out of service to perform testing, thus increasing the downtime and loss of data in the logical circuit. Moreover, if the failure cannot be isolated by the technicians in a LATA or the failure is located at the interface to the IEC, cooperative testing with the IEC must also be coordinated to isolate the failure leading to a further increase in downtime and loss of data in the network circuit.

It is with respect to these considerations and others that the present invention has been made.

SUMMARY

In accordance with the present invention, the above and other problems are solved by methods for method and system for automatically renaming logical circuit identifiers for rerouted logical circuits in a data network. According to one method, a first logical circuit identifier is identified for a first logical circuit in the data network. Next, a second logical circuit identifier for a second logical circuit is identified. The second logical circuit is utilized for rerouting data from the first logical circuit in the data network. The second logical circuit may be used for rerouting data in response to a failure in the first logical circuit. A comparison is then made between the first logical circuit identifier and the second logical identifier. If the first logical circuit identifier is different than the second logical identifier, then the first logical identifier is renamed to the second logical identifier without manual intervention.

The first logical identifier and the second logical identifier may be stored in a database. The first logical circuit identifier may be associated with the second logical identifier so that when a failure in the first logical circuit is corrected, the first logical circuit identifier may be reassigned to the first logical circuit. The second logical circuit may be a currently unused logical circuit in the data network. The logical circuit identifiers may be data link connection identifiers (“DLCIs”) or virtual path/virtual circuit identifiers (“VPI/VCIs”). The first and second logical circuits may be either permanent virtual circuits (“PVCs”) or switched virtual circuits (“SVCs”). The data network may be either a frame relay network or an asynchronous transfer mode (“ATM”) network.

According to another method, logical circuit identifiers are automatically renamed in response to a logical circuit failure in a data network. The method includes determining a failure in a first logical circuit in the data network, identifying a first logical circuit identifier for the first logical circuit in the data network, and identifying a second logical circuit identifier for a second logical circuit in the data network. The second logical circuit may be a logical failover circuit for rerouting data from the first logical circuit in the data network. The method further includes comparing the first logical circuit identifier to the second logical identifier. If the first logical circuit identifier is different than the second logical identifier, the method further includes renaming the first logical identifier to the second logical identifier without manual intervention, associating the first logical circuit identifier with the second logical identifier in a database, and determining whether the first logical circuit has been restored. If it is determined that the first logical circuit has been restored, then the second logical identifier is renamed back to the first logical identifier without manual intervention.

In accordance with other aspects, the present invention relates to a system for automatically renaming logical circuit identifiers in a data network. The system includes a network database for storing logical circuit identifiers for logical circuits in a data network. The system also includes a network management module in communication with the network database. The network management module identifies a first logical circuit identifier for a first logical circuit in the data network and identifies a second logical circuit identifier for a second logical circuit in the data network. The second logical circuit may be utilized for rerouting data from the first logical circuit in the data network. The network management module first compares the first logical circuit identifier to the second logical identifier and, if the first logical circuit identifier is different than the second logical identifier, then renames the first logical identifier to the second logical identifier in the network database without manual intervention.

These and various other features as well as advantages, which characterize the present invention, will be apparent from a reading of the following detailed description and a review of the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a data network according to an embodiment of the invention.

FIG. 2 illustrates a local access and transport area (“LATA”) in the data network of FIG. 1, according to an embodiment of the invention.

FIG. 3 illustrates a network management system which may be utilized to automatically rename logical circuit identifiers for rerouted logical circuits in the data network of FIG. 1, according to an embodiment of the invention.

FIG. 4 illustrates a failover data network for rerouting logical circuit data, according to an embodiment of the invention.

FIG. 5 illustrates a flowchart describing logical operations for automatically renaming logical circuit identifiers for rerouted logical circuits in the data network of FIG. 1, according to an embodiment of the invention.

FIG. 6 illustrates a table of mapped logical circuit IDs and logical failover circuit IDs for rerouted logical circuits, according to an embodiment of the invention.

DETAILED DESCRIPTION

Embodiments of the present invention provide for a method and system for automatically renaming logical circuit identifiers for rerouted logical circuits in a data network. In the following detailed description, references are made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments or examples. Referring now to the drawings, in which like numerals represent like elements through the several figures, aspects of the present invention and the exemplary operating environment will be described.

Embodiments of the present invention may be generally employed in a data network 2 as shown in FIG. 1. The data network 2 includes local access and transport areas (“LATAs”) 5 and 15 which are connected by an Inter-Exchange Carrier (“IEC”) 10. It should be understood that the LATAs 5 and 15 may be data networks operated by a commonly owned Local Exchange Carrier (“LEC”). It should be further understood that the IEC 10 may include one or more data networks which may be operated by a commonly owned IEC. It will be appreciated by those skilled in the art that the data network 2 may be a frame relay network, asynchronous transfer mode (“ATM”) network, or any other network capable of communicating data conforming to Layers 2-4 of the Open Systems Interconnection (“OSI”) model developed by the International Standards Organization, incorporated herein by reference. It will be appreciated that these networks may include, but are not limited to, communications protocols conforming to the Multiprotocol Label Switching Standard (“MPLS”) networks and the Transmission Control Protocol/Internet Protocol (“TCP/IP”), which are known to those skilled in the art.

The data network 2 includes a network circuit which channels data between a host device 112 and a remote device 114 through the LATA 5, the IEC 10, and the LATA 15. It will be appreciated by those skilled in the art that the host and remote devices 112 and 114 may be local area network (“LAN”) routers, LAN bridges, hosts, front end processors, Frame Relay Access Devices (“FRADs”), or any other device with a frame relay, ATM, or network interface. It will be further appreciated that in the data network 2, the LATAs 5 and 15 and the IEC 10 may include network elements (not shown) which support interworking to enable communications between host and remote devices supporting dissimilar protocols. Network elements in a data network supporting interworking may translate frame relay data packets or frames sent from a host FRAD to ATM data packets or cells so that a host device may communicate with a remote device having an ATM interface. The LATAs 5 and 15 and the IEC 10 may further include one or more interconnected network elements, such as switches (not shown), for transmitting data. An illustrative LEC data network will be discussed in greater detail in the description of FIG. 2 below.

The network circuit between the host device 112 and the remote device 114 in the data network 2 includes a physical circuit and a logical circuit. As used in the foregoing description and the appended claims, a physical circuit is defined as the physical path that connects the end point of a network circuit to a network device. For example, the physical circuit of the network circuit between the host device 112 and the remote device 114 includes the physical connection 121 between the host device 112 and the LATA 5, the physical connection 106 between the LATA 5 and the IEC 10, the physical connection 108 between the IEC 10 and the LATA 15, and the physical connection 123 between the LATA 15 and the remote device 114. Routers and switches within the LATAs 5 and 15 and the IEC 10 carry the physical signal between the host and remote end devices 112 and 114 through the physical circuit.

It should be understood that the host and remote devices may be connected to the physical circuit described above using user-to-network interfaces (“UNIs”). As is known to those skilled in the art, an UNI is the physical demarcation point between a user device (e.g., a host device) and a public data network. It will further be understood by those skilled in the art that the physical connections 106 and 108 may include trunk circuits for carrying the data between the LATAs 5 and 15 and the IEC 10. It will be further understood by those skilled in the art that the connections 121 and 123 may be any of various physical communications media for communicating data such as a 56 Kbps line or a T1 line carried over a four-wire shielded cable or over a fiber optic cable.

As used in the foregoing description and the appended claims, a logical circuit is defined as a portion of the network circuit wherein data is sent over variable communication data paths or logical connections established between the first and last network devices within a LATA or IEC network and over fixed communication data paths or logical connections between LATAs (or between IECs). Thus, no matter what path the data takes within each LATA or IEC, the beginning and end of each logical connection between networks will not change. For example, the logical circuit of the network circuit in the data network 2 may include a variable communication path within the LATA 5 and a fixed communication path (i.e., the logical connection 102) between the LATA 5 and the IEC 10. It will be understood by those skilled in the art that the logical connections 102 and 104 in the data network 2 may include network-to-network interfaces (“NNIs”) between the last sending switch in a LATA and the first receiving switch in an IEC.

As is known to those skilled in the art, each logical circuit in a data network may be identified by a unique logical identifier. In frame relay networks, the logical identifier is called a Data Link Connection Identifier (“DLCI”) while in ATM networks the logical identifier is called a Virtual Path Identifier/Virtual Circuit Identifier (“VPI/VCI”). In frame relay networks, the DLCI is a 10-bit address field contained in the header of each data frame and contains identifying information for the logical circuit as well as information relating to the destination of the data in the frame and service parameters for handling network congestion. For example, in the data network 2 implemented as a frame relay network, the designation DLCI 100 may be used to identify the logical circuit between the host device 112 and the remote device 114. It will be appreciated that in data networks in which logical circuit data is communicated through more than one carrier (e.g., an LEC and an IEC) the DLCI designation for the logical circuit may change in a specific carrier's network. For example, in the data network 2, the designation DLCI 100 may identify the logical circuit in the LATA 5 and LATA 15 but the designation DLCI 800 may identify the logical circuit in the IEC 10.

Illustrative service parameters which may be included in the DLCI include a Committed Information Rate (“CIR”) parameter and a Committed Burst Size (“Bc”) parameter. As is known to those skilled in the art, the CIR represents the average capacity of the logical circuit and the Bc represents the maximum amount of data that may be transmitted. It will be appreciated that the logical circuit may be provisioned such that when the CIR or the Bc is exceeded, the receiving switch in the data network will discard the frame. It should be understood that the logical circuit parameters are not limited to CIR and Bc and that other parameters known to those skilled in the art may also be provisioned, including, but not limited to, Burst Excess Size (“Be”) and Committed Rate Measurement Interval (“Tc”). In ATM networks, the VPI/VCI is an address field contained in the header of each ATM data cell and contains identifying information for the logical circuit as well as information specifying a data cell's destination and specific bits which may indicate, for example, the existence of congestion in the network and a threshold for discarding cells.

It should be understood that the logical circuit in the data network 2 may be a permanent virtual circuit (“PVC”) available to the network at all times or a temporary or a switched virtual circuit (“SVC”) available to the network only as long as data is being transmitted. It should be understood that the data network 2 may further include additional switches or other interconnected network elements (not shown) creating multiple paths within each LATA and IEC for defining each PVC or SVC in the data network. It will be appreciated that the data communicated over the logical connections 102 and 104 may be physically carried by the physical connections 106 and 108.

The data network 2 may also include a failover network 17 for rerouting logical circuit data, according to an embodiment of the invention. The failover network 17 may include a network failover circuit including physical connections 134 and 144 and logical connections 122 and 132 for rerouting logical circuit data in the event of a failure in the network circuit between the host device 112 and the remote device 114. The failover network 17 will be described in greater detail in the description of FIG. 4 below. The data network 2 may also include a network management system 175 in communication with the LATA 5, the LATA 15, and the failover network 17. The network management system 175 may be utilized to obtain status information for the logical and physical circuit between the host device 112 and the remote device 114. The network management system 175 may also be utilized for rerouting logical data in the data network 2 between the host device 112 and the remote device 114. The network management system 175 will be discussed in greater detail in the description of FIG. 3 below.

FIG. 2 illustrates the LATA 5 in the data network 2 described in FIG. 1 above, according to an embodiment of the present invention. As shown in FIG. 2, the LATA 5 includes interconnected network devices such as switches 186, 187, and 188. It will be appreciated that the data network 2 may also contain other interconnected network devices and elements (not shown) such as digital access and cross connect switches (“DACS”), channel service units (“CSUs”), and data service units (“DSUs”). As discussed above in the description of FIG. 1, the connection data paths of a logical circuit within a data network may vary between the first and last network devices in a data network. For example, as shown in FIG. 2, the logical circuit in the LATA 5 may include the communication path 185 between the switches 186 and 188 or the communication path 184 between the switches 186, 187, and 188. As discussed above, it should be understood that the actual path taken by data through the LATA 5 is not fixed and may vary from time to time, such as when automatic rerouting takes place.

It will be appreciated that the switches 186, 187, and 188 may include a signaling mechanism for monitoring and signaling the status of the logical circuit in the data network 2. Each time a change in the status of the logical circuit is detected (e.g., a receiving switch begins dropping frames), the switch generates an alarm or “trap” which may then be communicated to a management station, such as a logical element module (described in detail in the description of FIG. 3 below), in the network management system 175. In one embodiment, the signaling mechanism may be in accord with a Local Management Interface (“LMI”) specification, which provides for the sending and receiving of “status inquiries” between a data network and a host or remote device. The LMI specification includes obtaining status information through the use of special management frames (in frame relay networks) or cells (in ATM networks). In frame relay networks, for example, the special management frames monitor the status of logical connections and provide information regarding the health of the network. In the data network 2, the host and remote devices 112 and 114 receive status information from the individual LATAs they are connected to in response to a status request sent in a special management frame or cell. The LMI status information may include, for example, whether or not the logical circuit is congested or whether or not the logical circuit has failed. It should be understood that the parameters and the signaling mechanism discussed above are optional and that other parameters and mechanisms may also be utilized to obtain connection status information for a logical circuit.

FIG. 3 illustrates the network management system 175 which may be utilized to automatically reroute logical circuit data from a failed logical circuit in the data network of FIG. 1, according to an embodiment of the invention. The network management system 175 includes a service order system 160, a network database 170, a logical element module 153, a physical element module 155, a network management module 176, and a test module 180. The service order system 160 is utilized in the data network 2 for receiving service orders for provisioning network circuits. The service order includes information defining the transmission characteristics (i.e., the logical circuit) of the network circuit. The service order also contains the access speed, CIR, burst rates, and excess burst rates. The service order system 160 communicates the service order information to a network database 170 over management trunk 172. The network database 170 assigns and stores the parameters for the physical circuit for the network circuit such as a port number on the switch 186 for transmitting data over the physical connection 121 to and from the host device 112.

The network database 170 may also be in communication with an operations support system (not shown) for assigning physical equipment to the network circuit and for maintaining an inventory of the physical assignments for the network circuit. An illustrative operations support system is “TIRKS”® (Trunks Integrated Records Keeping System) marketed by TELECORDIA™ TECHNOLOGIES, Inc. of Morristown, N.J. The network database 170 may also be in communication with a Work Force Administration and Control system (“WFNC”) (not shown) used to assign resources (i.e., technicians) to work on installing the physical circuit.

The network management system 175 also includes the logical element module 153 which is in communication with the switches in the data network 2 through management trunks 183. The logical element module 153 runs a network management application program to monitor the operation of logical circuits which includes receiving trap data generated by the switches which indicate the status of logical connections. The trap data may be stored in the logical element module 153 for later analysis and review. The logical element module 153 is also in communication with the network database 170 via management trunks 172 for accessing information stored in the network database 170 regarding logical circuits, such as the logical circuit identifier data. The logical circuit identifier data may include, for example, the DLCI or VPI/VCI header information for each data frame or cell in the logical circuit including the circuit's destination and service parameters. The logical element module 153 may consist of terminals (not shown) that display a map-based graphical user interface (“GUI”) of the logical connections in the data network. An illustrative logical element module is the NAVISCORE™ system marketed by LUCENT TECHNOLOGIES, Inc. of Murray Hill, N.J.

The network management system 175 further includes the physical element module 155 in communication with the physical connections of the network circuit via management trunks (not shown). The physical element module 155 runs a network management application program to monitor the operation and retrieve data regarding the operation of the physical circuit. The physical element module 155 is also in communication with the network database 170 via management trunks 172 for accessing information regarding physical circuits, such as line speed. Similar to the logical element module 153, the physical logical element module 155 may also consist of terminals (not shown) that display a map-based GUI of the physical connections in the LATA 5. An illustrative physical element module is the Integrated Testing and Analysis System (“INTAS”), marketed by TELECORDIA™ TECHNOLOGIES, Inc. of Morristown, N.J., which provides flow-through testing and analysis of telephony services.

The physical element module 155 troubleshoots the physical connections for a physical circuit by communicating with test module 180, which interfaces with the physical connections via test access point 156. The test module 180 obtains the status of the physical circuit by transmitting “clean” test signals to test access point 156 (shown in FIG. 2) which “loops back” the signals for detection by the test module 180. It should be understood that there may be multiple test access points on each of the physical connections for the physical circuit.

The network management system 175 further includes the network management module 176 which is in communication with the service order system 160, the network database 170, the logical element module 153, and the physical element module 155 through communications channels 172. It should be understood that in one embodiment, the network management system 175 may also be in communication with the LATA 15, the IEC 10, and the failover network 17. The communications channels 172 may be on a LAN. The network management module 176 may consist of terminals (not shown), which may be part of a general-purpose computer system that displays a map-based GUI of the logical connections in data networks. The network management module 176 may communicate with the logical element module 153 and the physical element module 155 using a Common Object Request Broker Architecture (“CORBA”). As is known to those skilled in the art, CORBA is an open, vendor-independent architecture and infrastructure which allows different computer applications to work together over one or more networks using a basic set of commands and responses. The network management module 176 may also serve as an interface for implementing logical operations to provision and maintain network circuits. The logical operations may be implemented as machine instructions stored locally or as instructions retrieved from the logical and physical element modules 153 and 155. An illustrative method detailing the provisioning and maintenance of network circuits in a data network is presented in U.S. patent application Ser. No. 10/348,592, entitled “Method And System For Provisioning And Maintaining A Circuit In A Data Network,” filed on Jan. 23, 2003, and assigned to the same assignee as this application, which is expressly incorporated herein by reference. An illustrative network management module is the Broadband Network Management System® (“BBNMS”) marketed by TELECORDIA™ TECHNOLOGIES, Inc. of Morristown, N.J.

FIG. 4 illustrates an illustrative failover data network for rerouting logical circuit data, according to one embodiment of the present invention. As shown in FIG. 4, the failover network 17 includes an IEC 20, a LATA 25, and an IEC 30. The failover network further includes a network failover circuit which includes a physical failover circuit and a logical failover circuit. The physical failover circuit includes the physical connection 134 between the LATA 5 (shown in FIG. 1) and the IEC 20, the physical connection 136 between the IEC 20 and the LATA 25, the physical connection 138 between the LATA 25 and the IEC 30, and the physical connection 144 between the IEC 30 and the LATA 15 (shown in FIG. 1). Similarly, the logical failover circuit may include the logical connection 122 between the LATA 5 (shown in FIG. 1) and the IEC 20, the logical connection 124 between the IEC 20 and the LATA 25, the logical connection 126 between the LATA 25 and the IEC 30, and the logical connection 132 between the IEC 30 and the LATA 15 (shown in FIG. 1). It should be understood that in one embodiment, the network failover circuit illustrated in the failover network 17 may include a dedicated physical circuit and a dedicated logical circuit provisioned by a network service provider serving the LATAs 5, 15, and 25 and the IECs 20 and 30, for rerouting logical data from a failed logical circuit.

FIG. 5 illustrates a flowchart describing logical operations 500 for automatically rerouting logical circuit data in a data network, according to an embodiment of the invention. The logical operations 500 of FIG. 5 may be implemented using coded instructions (e.g., computer readable instructions) stored on one or more tangible and/or non-transitory computer readable media such as in the above-mentioned general-purpose computer and implementing one or more computer programs or computer applications. It will be appreciated that the logical operations 500 may be initiated by a customer report of a network circuit failure received in the data network 2. For example, a customer at the remote device 114 may determine that the remote device 114 is not receiving any data (e.g., frames or cells) sent from the host device 112 (e.g., by reviewing LMI status information in the host device). After receiving the customer report, the network service provider providing the network circuit may open a trouble ticket in the service order system 160 to troubleshoot the logical circuit.

The logical operations 500 begin at operation 505 where the network management module 176 determines a failure in a logical circuit in the data network 2. It should be understood that a logical circuit failure occurs when one or more logical connections in a logical circuit have failed. As discussed above in the description of FIG. 2, trap data indicating a logical connection failure may include status information indicating that a switch in the data network is discarding frames or cells. Such an event may occur, for example, when the maximum CIR or Bc (as specified in the DLCI of a frame in a frame relay network, for example) is exceeded. For example, in the data network 2 shown in FIG. 1, the “X” marking the logical connections 102 and 104 indicate that both connections are “down beyond” (i.e., not communicating data) the NNIs for the logical circuit in the LATA data networks 5 and 15. In this example, such a condition may indicate that the logical circuit failure lies in the IEC data network 10.

The trap data may be received from the logical element module 153 and may be generated by one or more switches in the data network which indicate the status of one or more logical connections making up the logical circuit. It will be appreciated that in one embodiment of the present invention, the communication of the trap data for the logical circuit may be manually initiated by a technician from a terminal in the network management module 176. In another embodiment of the present invention, the network management module 176 may be configured to automatically monitor the logical circuits for trap data to identify the logical circuit failure. An illustrative method detailing the automatic monitoring of logical circuits to identify a logical circuit failure in a data network is presented in co-pending U.S. patent application Ser. No. 10/745,170, entitled “Method And System For Automatically Identifying A Logical Circuit Failure In A Data Network,” filed on Dec. 23, 2003, and assigned to the same assignee as this patent, which is expressly incorporated herein by reference. The logical operations 500 then continue from operation 505 to operation 510.

If at operation 510, it is determined that a logical circuit failure has not occurred, the logical operations 500 then return to operation 505 where the network management module 176 again determines a failure status for the logical circuit. If, however, at operation 510 it is determined that a logical circuit failure has occurred, the logical operations continue to operation 515. At operation 515, the network management module 176 identifies a logical circuit identification (ID) for the failed logical circuit by accessing the network database 170. The logical operations then continue from operation 515 to operation 520. At operation 520, the network management module 176 identifies an ID for a logical failover circuit for rerouting the data from the failed logical circuit. It should be understood that in identifying the ID for the logical failover circuit, the network management module 176 initiates a reroute procedure for rerouting the data from the failed logical circuit to a logical failover circuit in the failover network 17. An illustrative method detailing the rerouting of logical circuit data to a logical failover circuit is presented in co-pending U.S. patent application Ser. No. 10/744,921 entitled “Method And System For Automatically Rerouting Logical Circuit Data In A Data Network,” filed on Dec. 23, 2003, and assigned to the same assignee as this patent, which is expressly incorporated herein by reference.

At operation 525, the network management module 176 compares the ID (e.g. the DLCI or VPI/VCI of the failed logical circuit to the ID of the logical failover circuit. If at operation 525, it is determined that the IDs of the failed logical circuit and the logical failover circuit are the same, the logical operations 500 then end. It will be appreciated that in the failover network 17, a dedicated logical failover circuit may be assigned to an existing logical circuit in the data network 2 and identified with the same ID as the failed logical circuit.

If, however, at operation 525 it is determined that logical circuit IDs of the failed logical circuit and the logical failover circuit are not the same, the logical operations 500 then continue from operation 525 to operation 530 where the network management module 176 renames the logical circuit ID of the failed logical circuit to the ID of the logical failover circuit in the database 170. It should be understood that a logical failover circuit which is already an existing logical circuit (i.e., normally communicates data traffic in a data network) is already assigned a unique logical circuit ID. Thus, in the presently described embodiment of the invention, the logical identifier of a failed logical circuit may be renamed so that it is in accord with a current logical identifier of a logical failover circuit. For example, in a frame relay network, a logical circuit may be identified as DLCI 100 while a logical failover circuit may be identified as DLCI 250. When the logical circuit fails, it is renamed from DLCI 100 to DLCI 250. The logical operations 500 then continue from operation 530 to operation 535.

At operation 535, the network management module 176 associates or “maps” the failed logical circuit ID to the logical failover circuit ID in the network database 170. An illustrative table of mapped logical circuit IDs and logical failover circuit IDs is shown in FIG. 6, which will be discussed in greater detail below. The logical operations 500 then continue from operation 535 to operation 540. At operation 540, the network management module 176, upon determining that the failed logical circuit has been restored, renames the logical circuit ID of the logical failover circuit back to the ID of the restored logical circuit in the network database 170. It will be appreciated that the network management module may determine that the failed logical circuit has been restored based on updated trap data received from the logical element module 153. The logical operations 500 then end.

FIG. 6 illustrates a table of mapped logical circuit IDs and logical failover circuit IDs which may be stored in the network database 170, according to an embodiment of the invention. As shown in FIG. 6, the table includes a logical circuit ID column 52, a logical failover circuit ID column 54, and a reroute map column 56. The logical circuit ID column 52 lists the current logical circuit IDs for logical circuits in the data network 2. The logical failover circuit ID column 54 lists the IDs for logical circuits selected as failover logical circuits for rerouting logical circuit data. As discussed above, the failover logical circuits may be dedicated logical circuits in the failover network 17 for rerouting logical circuit data. Alternatively, the failover logical circuits may be existing but currently unused logical circuits in the data network 2 which are utilized for rerouting logical circuit data. For example, in row 58 the logical circuit ID 100 is shown associated with a logical failover circuit ID 250. That is, a logical failover circuit having an ID of 250 has been selected to reroute data from the logical circuit having an ID of 100 due to a failure in that logical circuit. The reroute map data for row 58 indicates that the ID of the failed logical circuit (100) has been mapped to the failover ID (250) in the database. As discussed above in FIG. 5, when the failure in the logical circuit has been restored, the network management module 176 may utilize the map data in the table to rename the restored logical circuit to its original ID.

It will be appreciated that the embodiments of the invention described above provide for a method and system for automatically renaming logical circuit identifiers for rerouted logical circuits in a data network. The various embodiments described above are provided by way of illustration only and should not be construed to limit the invention. Those skilled in the art will readily recognize various modifications and changes that may be made to the present invention without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the present invention, which is set forth in the following claims. 

1. A method comprising: identifying a first logical circuit identifier for a first logical circuit in a first network; and when a failure is detected in the first logical circuit: identifying a second logical circuit identifier for a second logical circuit in a failover network separate from the first network, the second logical circuit to reroute data from the first logical circuit; and renaming the first logical circuit without manual intervention to identify the first logical circuit using the second logical circuit identifier.
 2. The method of claim 1, wherein the first network includes a first local access and transport area (LATA) and a second LATA and the first logical circuit traverses the first and second LATAs.
 3. The method of claim 2, further comprising operating a network management system to detect the failure in the first logical circuit, the network management system in communication with the first and second LATAs and the failover network through management trunks.
 4. The method of claim 3, further comprising operating the network management system to: obtain status information associated with the first logical circuit from at least one of a plurality of switches forming the first logical circuit, the plurality of switches separate from the network management system; detect the failure in the first logical circuit based on the status information; and reroute the data via the second logical circuit in response to detecting the failure.
 5. The method of claim 2, wherein the failover network includes a third LATA in communication with the first LATA via a first inter-exchange carrier (IEC) and in communication with the second LATA via a second IEC.
 6. The method of claim 1, further comprising, when the failure is detected in the first logical circuit, mapping the first logical circuit identifier to the second logical circuit identifier in a data structure, and further comprising, when the first logical circuit is restored, accessing the first logical circuit identifier in the data structure based on the mapping and renaming the first logical circuit to identify the first logical circuit using the first logical circuit identifier.
 7. The method of claim 1, wherein the failure is detected in the first logical circuit when at least one logical connection of the first logical circuit is not communicating data.
 8. A system comprising: a logical element module in communication with switches forming a first logical circuit in a first network and to receive status information from the switches associated with the first logical circuit; and a network management module to: identify a first logical circuit identifier for the first logical circuit; and when a failure is detected in the first logical circuit based on the status information: identify a second logical circuit identifier for a second logical circuit in a failover network separate from the first network, the second logical circuit to reroute data from the first logical circuit; and rename the first logical circuit without manual intervention to identify the first logical circuit using the second logical circuit identifier.
 9. The system of claim 8, wherein the first network includes a first local access and transport area (LATA) and a second LATA and the first logical circuit traverses the first and second LATAs.
 10. The system of claim 9, wherein the logical element module is in communication with the switches in the first and second LATAs through management trunks.
 11. The system of claim 9, wherein the failover network includes a third LATA in communication with the first LATA via a first inter-exchange carrier (IEC) and in communication with the second LATA via a second IEC.
 12. The system of claim 8, wherein the logical element module and the network management module are separate from the switches forming the first logical circuit.
 13. The system of claim 8, wherein the network management module is to: map the first logical circuit identifier to the second logical circuit identifier in a data structure when the failure is detected in the first logical circuit; and when the first logical circuit is restored, access the first logical circuit identifier in the data structure based on the mapping and rename the first logical circuit to identify the first logical circuit using the first logical circuit identifier.
 14. The system of claim 8, wherein the failure is detected in the first logical circuit when at least one logical connection of the first logical circuit is not communicating data.
 15. A non-transitory computer readable medium having instructions stored thereon that, when executed, cause a machine to at least: identify a first logical circuit identifier for a first logical circuit in a first network; and when a failure is detected in the first logical circuit: identify a second logical circuit identifier for a second logical circuit in a failover network separate from the first network, the second logical circuit to reroute data from the first logical circuit; and rename the first logical circuit without manual intervention to identify the first logical circuit using the second logical circuit identifier.
 16. The non-transitory computer readable medium of claim 15, wherein the first network includes a first local access and transport area (LATA) and a second LATA and the first logical circuit traverses the first and second LATAs.
 17. The non-transitory computer readable medium of claim 16 having instructions stored thereon that, when executed, cause the machine to detect the failure in the first logical circuit, the machine in communication with the first and second LATAs and the failover network through management trunks.
 18. The non-transitory computer readable medium of claim 17 having instructions stored thereon that, when executed, cause the machine to: obtain status information associated with the first logical circuit from at least one of a plurality of switches forming the first logical circuit, the plurality of switches separate from the machine; detect the failure in the first logical circuit based on the status information; and reroute the data via the second logical circuit in response to detecting the failure.
 19. The non-transitory computer readable medium of claim 16, wherein the failover network includes a third LATA in communication with the first LATA via a first inter-exchange carrier (IEC) and in communication with the second LATA via a second IEC.
 20. The non-transitory computer readable medium of claim 15 having instructions stored thereon that, when executed, cause the machine to: when the failure is detected in the first logical circuit, map the first logical circuit identifier to the second logical circuit identifier in a data structure; and when the first logical circuit is restored, access the first logical circuit identifier in the data structure based on the mapping and rename the first logical circuit to identify the first logical circuit using the first logical circuit identifier. 